
/*
** Tag methods
** See Copyright Notice in lua.h
*/

#include <string.h>

#define ltm_c

#include "lua.h"

#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"

const char *const luaT_typenames[] = {
  "nil", "boolean", "userdata", "number",
  "string", "table", "function", "userdata", "thread"
};

void
luaT_init(lua_State * L)
{
  static const char *const luaT_eventname[] = { /* ORDER TM */
    "__index", "__newindex",
    "__gc", "__mode", "__eq",
    "__add", "__sub", "__mul", "__div",
    "__pow", "__unm", "__lt", "__le",
    "__concat", "__call"
  };
  int i;
  for (i = 0; i < TM_N; i++) {
    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
    luaS_fix(G(L)->tmname[i]);  /* never collect these names */
  }
}

/*
** function to be used with macro "fasttm": optimized for absence of
** tag methods
*/
const TObject *
luaT_gettm(Table * events, TMS event, TString * ename)
{
  const TObject *tm = luaH_getstr(events, ename);
  lua_assert(event <= TM_EQ);
  if (ttisnil(tm)) {            /* no tag method? */
    events->flags |= cast(lu_byte, 1u << event);        /* cache this fact */
    return NULL;
  } else
    return tm;
}

const TObject *
luaT_gettmbyobj(lua_State * L, const TObject * o, TMS event)
{
  TString *ename = G(L)->tmname[event];
  switch (ttype(o)) {
  case LUA_TTABLE:
    return luaH_getstr(hvalue(o)->metatable, ename);
  case LUA_TUSERDATA:
    return luaH_getstr(uvalue(o)->uv.metatable, ename);
  default:
    return &luaO_nilobject;
  }
}

/*
 * Local Variables:
 * c-basic-offset: 2
 * indent-tabs-mode: nil
 * End:
 */
